Relativistic Corrections of Closed-shell Atomic Systems

Relativistic corrections in magnetic systems

We present a weak-relativistic limit comparison between the Kohn-Sham-Dirac equation and its approximate form containing the exchange coupling, which is used in almost all relativistic codes of density-functional theory. For these two descriptions, an exact expression of the Dirac Green’s function in terms of the nonrelativistic Green’s function is first derived and then used to calculate the e...

Relativistic corrections to the electromagnetic polarizabilities of compound systems

The low-energy amplitude of Compton scattering on the bound state of two charged particles of arbitrary masses, charges and spins is calculated. A case in which the bound state exists due to electromagnetic interaction (QED) is considered. The term, proportional to ω2, is obtained taking into account the first relativistic correction. It is shown that the complete result for this correction dif...

Formulations of the closed-shell interactions in endohedral systems.

An attempt is made to express the interaction energy in an endohedral A@B system starting from a one-center (r(<))(l)/(r(>))(l+1) expansion. Electrostatic, induction, and dispersion contributions are obtained from Rayleigh-Schrödinger perturbation theory. New electric polarizabilities with r(-l-1) radial integrals are calculated for l = 0, 1 and 2 for the outer system B. For a 'breakable'B, the...

A closed-shell coupled-cluster treatment of the Breit-Pauli first-order relativistic energy correction.

First-order relativistic corrections to the energy of closed-shell molecular systems are calculated, using all terms in the two-component Breit-Pauli Hamiltonian. In particular, we present the first implementation of the two-electron Breit orbit-orbit integrals, thus completing the first-order relativistic corrections within the two-component Pauli approximation. Calculations of these correctio...

Effective Hamiltonians with Relativistic Corrections